LONDON — Canada's Milos Raonic enjoyed a winning return from a back injury on Wednesday.

The No. 5 seed from Thornhill, Ont., downed Italy's Marco Cecchinato 6-3, 6-2 in a first-round match at the Queen's Club grass-court tournament.

Raonic, ranked 18th in the world, pulled out of the Stuttgart Open last Saturday with back issues prior to a scheduled semifinal against fellow Canadian Felix Auger-Aliassime.

On Wednesday, Raonic had 24 aces, 19 more than world No. 40 Cecchinato. The Canadian won 90 per cent of his points on first serve and faced just one break point.

Raonic will meet qualifier Aljaz Bedene of Slovenia in the second round of the ATP Tour 500 event.

Earlier, Canadian Denis Shapovalov's struggles continued with a 7-5, 6-4 loss to No. 3 seed Juan Martin del Potro of Argentina in a first-round match.

The 20-year-old from Richmond Hill, Ont., ranked 25th in the world, is now 2-8 since March.

Shapovalov, of Richmond Hill, Ont., didn't have one break-point opportunity against world No. 12 del Potro.

The 2009 U.S. Open champ was to face Spain's Feliciano Lopez in the second round of the tune-up tourney for Wimbledon, but withdrew because of a knee injury after slipping near the net against Shapovalov.

The eighth-seeded Auger-Aliassime's match against Grigor Dimitrov of Bulgaria was postponed because of rain.